Dear Yujie,

At first I thought this looked just like diffraction of multiple salt crystals, 
but there are perhaps a couple of rows of regularly spaced spots from a protein 
crystals. However, I think any program will struggle to get anything useful 
from this. 
Perhaps focussing a small beam (ideally microbeam) on different parts of the 
elongated clusters might get more single-crystal diffraction. 
Seeding using these crystal parts may also yield larger single crystals for 
higher resolution single crystal diffraction...



PS Anyone agree the crystals look like witches brooms? The stick part of the 
broom may be the single crystal.

Mark J van Raaij
Dpto de Estructura de Macromoleculas
Centro Nacional de Biotecnologia - CSIC
calle Darwin 3
E-28049 Madrid, Spain
tel. (+34) 91 585 4616

> On 12 Oct 2016, at 08:54, Liu Rachel <> wrote:
> Dear everyone:
> Recently, I suffered a problem during my research work. I purified a zinc 
> finger protein, and crystallized as a beautiful cube in a reservoir solution 
> only containing phosphate as the precipitant, no other buffer or molecules. 
> However, regardless of multiple optimization, the crystal diffracted badly 
> (7~8 Å best). I have also tried co-crystallization with dsRNA because this 
> protein can  bind to dsRNA. Then crystals grow in a new condition(2.5M 
> (NH4)2SO4,0.1M BTP,  pH7.0)and its form change to cluster of needle. But the 
> X-ray diffraction diagram is very strange(as shown in the picture). The Data 
> cannot be processed with HKL2000 either. I want to figure out, could this be 
> a RNA crystal rather than the complex?   Or is there anybody know about the 
> crystal of RNA molecular?
> Thank you very much!
> Yujie Liu 
> Room 2071, research center in life sciences,
> China Agricultural University 
> No. 2 yuanmingyuan west road, Haidian District, Beijing, 100193  P.R. China 
> Tel: (86)-10-62734078
> <crystal.jpg><lyj.png>

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